Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats
Repeated exposure to an anxiogenic stressor (AS) is a known environmental factor for the development of depression, yet the progression of sleep-wake (S-W) changes associated with the onset of AS-induced depression (ASID) is not completely understood. Thus, the aim of this study was to identify thes...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-02-01
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| Series: | Frontiers in Neurology |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00015/full |
| _version_ | 1819058730544660480 |
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| author | Matthew W O'Malley Rachel Lea eFishman Domenic A Ciraulo Subimal eDatta |
| author_facet | Matthew W O'Malley Rachel Lea eFishman Domenic A Ciraulo Subimal eDatta |
| author_sort | Matthew W O'Malley |
| collection | DOAJ |
| description | Repeated exposure to an anxiogenic stressor (AS) is a known environmental factor for the development of depression, yet the progression of sleep-wake (S-W) changes associated with the onset of AS-induced depression (ASID) is not completely understood. Thus, the aim of this study was to identify these progressive S-W changes by developing ASID in rats, via repeated exposure to an AS, and compare this ASID-associated sleep phenotype with the sleep phenotype of human depression. To achieve this aim, rats were first recorded for a 6-h period of baseline S-W activity without AS. Then, rats were subjected to five days of AS [Day 1: inescapable foot-shock; 5 trials of 3-s foot-shocks (1.0 mA) at 3-min intervals; Days 3-5: 15 trials of 5-s foot-shocks at 45-s intervals]. S-W activity was recorded for 6 h immediately after each AS treatment session. Two days later rats were again recorded for 6 h of S-W activity, but with no exposure to the AS (NASD). Compared to the baseline day: Day 1 of AS (ASD-1) increased wakefulness, slow-wave sleep (SWS) latency, and REM sleep latency, but decreased the total amount of REM sleep; ASD-2 animals remained awake throughout the 6-h S-W recording period; ASD-3, ASD-4, and ASD-5 (ASDs-3-5) decreased wakefulness, SWS latency, and REM sleep latency, but increased the total amount of REM sleep. Interestingly, these results reveal that initial exposure to the AS versus later, repeated exposure to the AS produced opposing S-W changes. On NASD, animals exhibited baseline-like S-W activity, except slightly less REM sleep. These results suggest that repeated AS produces a sleep phenotype that resembles the sleep phenotype of depression in humans, but consistent re-exposure to the AS is required. These results are promising because the methodological simplicity and reversibility of the ASID-associated S-W phenotype could be more advantageous than other animal models for studying the pathophysiological mechanisms that underlie the expression of ASID. |
| first_indexed | 2024-12-21T13:59:51Z |
| format | Article |
| id | doaj.art-7404c0be58c44c50a5f496aff755e748 |
| institution | Directory Open Access Journal |
| issn | 1664-2295 |
| language | English |
| last_indexed | 2024-12-21T13:59:51Z |
| publishDate | 2013-02-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Neurology |
| spelling | doaj.art-7404c0be58c44c50a5f496aff755e7482022-12-21T19:01:24ZengFrontiers Media S.A.Frontiers in Neurology1664-22952013-02-01410.3389/fneur.2013.0001543003Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in ratsMatthew W O'Malley0Rachel Lea eFishman1Domenic A Ciraulo2Subimal eDatta3Boston University School of MedicineBoston University School of MedicineBoston University School of MedicineBoston University School of MedicineRepeated exposure to an anxiogenic stressor (AS) is a known environmental factor for the development of depression, yet the progression of sleep-wake (S-W) changes associated with the onset of AS-induced depression (ASID) is not completely understood. Thus, the aim of this study was to identify these progressive S-W changes by developing ASID in rats, via repeated exposure to an AS, and compare this ASID-associated sleep phenotype with the sleep phenotype of human depression. To achieve this aim, rats were first recorded for a 6-h period of baseline S-W activity without AS. Then, rats were subjected to five days of AS [Day 1: inescapable foot-shock; 5 trials of 3-s foot-shocks (1.0 mA) at 3-min intervals; Days 3-5: 15 trials of 5-s foot-shocks at 45-s intervals]. S-W activity was recorded for 6 h immediately after each AS treatment session. Two days later rats were again recorded for 6 h of S-W activity, but with no exposure to the AS (NASD). Compared to the baseline day: Day 1 of AS (ASD-1) increased wakefulness, slow-wave sleep (SWS) latency, and REM sleep latency, but decreased the total amount of REM sleep; ASD-2 animals remained awake throughout the 6-h S-W recording period; ASD-3, ASD-4, and ASD-5 (ASDs-3-5) decreased wakefulness, SWS latency, and REM sleep latency, but increased the total amount of REM sleep. Interestingly, these results reveal that initial exposure to the AS versus later, repeated exposure to the AS produced opposing S-W changes. On NASD, animals exhibited baseline-like S-W activity, except slightly less REM sleep. These results suggest that repeated AS produces a sleep phenotype that resembles the sleep phenotype of depression in humans, but consistent re-exposure to the AS is required. These results are promising because the methodological simplicity and reversibility of the ASID-associated S-W phenotype could be more advantageous than other animal models for studying the pathophysiological mechanisms that underlie the expression of ASID.http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00015/fullAnxietyDepressionrat modelSleep-wakefoot-shock |
| spellingShingle | Matthew W O'Malley Rachel Lea eFishman Domenic A Ciraulo Subimal eDatta Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats Frontiers in Neurology Anxiety Depression rat model Sleep-wake foot-shock |
| title | Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats |
| title_full | Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats |
| title_fullStr | Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats |
| title_full_unstemmed | Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats |
| title_short | Effect of five-consecutive-day exposure to an anxiogenic stressor on sleep-wake activity in rats |
| title_sort | effect of five consecutive day exposure to an anxiogenic stressor on sleep wake activity in rats |
| topic | Anxiety Depression rat model Sleep-wake foot-shock |
| url | http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00015/full |
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